Function fold_left 

pub fn fold_left<'a, FnBrand, Brand: Kind_cdc7cd43dac7585f, A: 'a + Clone, B: 'a, FA, Marker>(
    func: impl FoldLeftDispatch<'a, FnBrand, Brand, A, B, FA, Marker>,
    initial: B,
    fa: FA,
) -> B

Folds a structure from the left.

Dispatches to Foldable::fold_left or RefFoldable::ref_fold_left based on whether the closure takes A or &A.

The Marker and FA type parameters are inferred automatically by the compiler from the closure’s argument type and the container argument.

Type Signature

forall Brand A B. Foldable Brand => ((B, A) -> B, B, Brand A) -> B

Type Parameters

• 'a: The lifetime of the values.
• FnBrand: The brand of the cloneable function to use.
• Brand: The brand of the foldable structure.
• A: The type of the elements.
• B: The type of the accumulator.
• FA: The container type (owned or borrowed), inferred from the argument.
• Marker: Dispatch marker type, inferred automatically.

Parameters

• func: The folding function.
• initial: The initial accumulator value.
• fa: The structure to fold (owned for Val, borrowed for Ref).

Returns

The final accumulator value.

Examples

use fp_library::{
	brands::*,
	functions::explicit::*,
	types::*,
};

// By-value
let result = fold_left::<RcFnBrand, VecBrand, _, _, _, _>(|b, a| b + a, 0, vec![1, 2, 3]);
assert_eq!(result, 6);

// By-ref
let lazy = RcLazy::new(|| 10);
let result =
	fold_left::<RcFnBrand, LazyBrand<RcLazyConfig>, _, _, _, _>(|b, a: &i32| b + *a, 5, &lazy);
assert_eq!(result, 15);